CVE-2018-21035 : What You Need to Know

Until version 5.14.1 of Qt, the WebSocket implementation allows the usage of frames and messages of up to 2GB in size, with no possibility of adjusting smaller limits. This vulnerability increases the risk of denial of service attacks by consuming excessive memory.

Understanding CVE-2018-21035

In Qt through 5.14.1, the WebSocket implementation accepts up to 2GB for frames and 2GB for messages. Smaller limits cannot be configured, making it easier for attackers to cause a denial of service through memory consumption.

What is CVE-2018-21035?

Vulnerability in Qt WebSocket implementation allowing frames and messages up to 2GB, posing a risk of denial of service attacks.

The Impact of CVE-2018-21035

CVSS v3.0 Base Score: 8.6 (High Severity)
Attack Complexity: Low
Attack Vector: Network
Availability Impact: High
No impact on Confidentiality or Integrity
No privileges required
Scope: Changed
User Interaction: None

Technical Details of CVE-2018-21035

Vulnerability Description

WebSocket implementation in Qt allows large frames and messages, leading to potential denial of service attacks.

Affected Systems and Versions

Product: Qt
Vendor: Qt
Versions affected: Until 5.14.1

Exploitation Mechanism

Attackers can exploit the WebSocket vulnerability to cause denial of service by consuming excessive memory.

Mitigation and Prevention

Immediate Steps to Take

Update Qt to versions beyond 5.14.1 to mitigate the vulnerability.
Monitor memory consumption for unusual patterns that could indicate an ongoing attack.

Long-Term Security Practices

Regularly update software and libraries to patch known vulnerabilities.
Implement network monitoring to detect and respond to abnormal traffic patterns.

Patching and Updates

Apply security patches provided by Qt to address the WebSocket vulnerability.